@@ -257,9 +257,6 @@ static void rcar_du_crtc_update_planes(struct rcar_du_crtc *rcrtc)
* resulting in visible flicker. To mitigate the issue only update the
* association if needed by enabled planes. Planes being disabled will
* keep their current association.
- *
- * To mitigate the issue further we could pre-associate planes with
- * CRTCs, either with a fixed 4/4 split, or through a module parameter.
*/
mutex_lock(&rcrtc->group->lock);
@@ -765,10 +765,11 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
rgrp->index = i;
rgrp->num_crtcs = min(rcdu->num_crtcs - 2 * i, 2U);
- /* Pre-associate all hardware planes with the first CRTC in the
- * group.
+ /* If we have more than one CRTCs in this group pre-associate
+ * planes 0-3 with CRTC 0 and planes 4-7 with CRTC 1 to minimize
+ * flicker occurring when the association is changed.
*/
- rgrp->dptsr_planes = 0;
+ rgrp->dptsr_planes = rgrp->num_crtcs > 1 ? 0xf0 : 0;
ret = rcar_du_planes_init(rgrp);
if (ret < 0)
If we have more than one CRTCs in a group pre-associate planes 0-3 with CRTC 0 and planes 4-7 with CRTC 1 to minimize flicker occurring when the association is changed. The pre-association could be controlled by a module parameter if needed. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 3 --- drivers/gpu/drm/rcar-du/rcar_du_kms.c | 7 ++++--- 2 files changed, 4 insertions(+), 6 deletions(-)